Scale Model Shop

Collapse

Airbrushing!!! "Everything you wanted to know but were afraid to ask"

Collapse
This topic is closed.
X
X
 
  • Time
  • Show
Clear All
new posts
  • Guest

    #16
    Part Two Of The Airbrush Guide

    Well we have discovered what an airbrush is and the types you can buy, now what can it do ????

    First of all the question you should ask is what medium i need to spray?

    The second question is what do i want to spray? Il assume this is models lol!

    What are we spraying Acrylics,Enamels,ink Or cellulose! now that is a different kettle of fish!

    What we need to look at first of all is paint thinning. For enamels acrylics the paint needs to be the consistency of milk this will allow you to spray a broad range of patterns from fine line to infill. Of course you can use a thicker mix with higher airpressure and a more open nozzle or a thinner mixture with less pressure and a more closed nozzle (gets simpler eh?) The thing is as you get more experienced you alter your mixes to accomodate the finish and the piece you are painting! For instance if you use too thick a mix with too much pressure the finish wil dry too quick or even dry before it hits the surface resulting in a coarse sandy texture on the surface this is bad!!! But if your painting a afv and you want a cast texture then this is good!!!! Too thin you will get paint runs or too much pressure, too close you will get spider legs.ut then again too thin is ok if you want a wash or tint. the secret is in the air pressure and paint flow. In other words practice experiment and be prepared to start again. Do not go out and buy a brush thinking it will give you a great finish !! it wont only you can do that with practice and perciverance. In the same thought if you buy a top of the range Iwata Micron be prepared for frustration It is an expensive bit of kit capable of producing lines a hairsbreadth thick, but totally impractical for painting a large scale model. Its like buying a 000 sable and trying to paint your model with that.(great for fine detail but sod all use for anything else). Once you are happy with a mix you are ready to start spraying. Before you approach your model try it out on a bit of paper first of all so you know you have the correct pressure and paint flow. Believe it or not i have a bit of wall next to my bench where much to the wifes displeasure i tune my brush. It is covered with squiggles and signatures where i get the pressure and flow right before i approach the model.(this is not a general recomendation though as it does cause extreme discomfort on occasions) Another important bit of advice is if you are about to spray your model, your brush is 2" from the surface , you press the trigger and pull slowly back to the point you set, and shock horror no paint flow!!!! DO NOT repeat DO NOT keep pulling the trigger back as if your lucky nothing will happen, if your not a huge wash of paint will erupt and ruin your day. If the paint doesnt flow its for three reasons

    1 the paint is too thick

    2 the air pressure is too low

    3 your nozzle is blocked because of paint lumps or foreign bodies in the mix.

    The only answer is to empty and clean out before restarting. Though you can minimise this by filtering your paint through the mesh on a pair of old tights. but make sure the mrs is not around before you liberate them.

    Getting on to cellulose. this needs to be a really wet mix ie thinned really well as it is so volatile it has a tendancy to dry before it reaches the surface giving an orange peel effect to the finish, this can be countered by spraying thinners directly onto the surface to help even it out but it is not really recomended. Much better to use very thin coats and build up the colour gradually, this should be done using a really low pressure whilst keeping the brush moving all the time, and remembering to lift the finger from the air trigger before moving the brush away from the model.

    Trying to tell people all this is probably very hit and miss! you see the important thing is to get used to your brush learn its limitations, its strengths, Is it happy spraying spraying ultra thin lines or lines perhaps a couple of mill wide will it be capable of large amounts of infill? Is the paint cup big enough not to have to refill it every 20 secs. Does it feel comfortable to hold. Does it make you want to paint??? All these points are something you may like to ponder, but in the end an experienced person with a cheap brush can produce work infinately beter than an inexperienced one with an expensive one.

    Comment

    • Guest

      #17
      Nigel,

      In my very basic trials with a brush the one thing that I find the biggest chore is the whole process of cleaning it out afterwards. Are there any short cuts or quick fixes to help with making this task any easier?

      Also another worry I have is putting the brush down while I reposition the job and the paint starts to dry on the brush. Is this a realistic worry and if so should the job be thought out sufficiently well enough to ensure that the painting can be done as quickly as possible without interruptions?

      Thanks for the guidance, I really enjoy your tutorial and the further questions it generates.

      Comment

      • Guest

        #18
        I used my airbursh for years when making fishing lures and was very happy with the results, the paint was just straight enamels and polyurethane varnish.

        I fancy giving acrylics a try but dread them 'solidifying' in the nozzle or something, with enamels I culd just do that 'cover the nozzle and blow back' routine'....but can I do that with enamels? Do they dry too quick? Am I just panicking for nothing?....Cheers

        Comment

        • Guest

          #19
          Replys

          Richard!

          First you can buy a can of "spray away" or sometimes called liquid reamer" this you just spray into the paint cup and nozzle and blow it through dead easy and i use it all the time. (this only applies to enamels though) As for putting the brush down I have made a simple holder from an old coat hanger that supports the brush stopping the contents from spilling out (dead easy and about 10p cost) basically its just a hook with 2 prongs screwed to the wall! As to paint drying in the brush if you just blow through air with no paintflow you shouldnt have that problem.

          Pingu lol!

          Yes you are panicking acrylics do tend to dry quicker in some cases but you would have to leave the brush for a good hour for this to be a problem! I personnaly dont like acrylics I find the finish and coverage when painting plastic models to be a lot less durable or even a lot less opaque. This to me means more paint and more effort to achieve a result also the curing time is far longer when you need to remask. some people swear by them but i have not found them (for my purposes) to offer any benefit at all.

          If you worry about clogged nozzles or airways a 10 minute soak in cellulose thinners wil cure all just make sure you blow some spray away or a mixture of thinners and very light machine oil through to keep the packing glands from breaking or drying up.

          Comment

          • Guest

            #20
            For the third part

            I was thinking along the lines of some video ?? what i need from you guys is the type of airbrush work you would like to see??

            Comment

            • wonwinglo
              • Apr 2004
              • 5410

              #21
              ***Show us some detail work Nigel,getting down to those fine lines etc,thank you.

              I was thinking along the lines of some video ?? what i need from you guys is the type of airbrush work you would like to see??

              Comment

              • Guest

                #22
                Air brush tutorial part 3

                I was going to do a bit on fine detail But before we get to that it seems one of the things that put people off airbrushing is the CLEANING!!!!

                So Here is a guide on how easy it is to keep your brush spick and span

                If your airbrush has been unused for a while you may find it has seized or become blocked! If this is the case just disasemble it and soak it in cellulose thinners, this will dissolve all kinds of dried paint, varnish, etc. Then use a pipe cleaner soaked in thinners to clean through the body this will get rid of any last spots of crud. A cotton bud is also indespensible for cleaning the recesses in your paint cup and nozzle (make sure your needle is withdrawn first though) I then find it advisable to use a bit of sewing machine oil soaked in a kitchen towel to wipe the needle before reinserting it into the body (if some of your brushes are as old as mine they will have leather or rubber packing glands this stops them cracking!) the newer ones have teflon seals that need virtually no mntainance.

                So you have just used a colour and now you want to switch. There are 2 things that you can do

                1 fill the paint resevior with thinner and blow it through untill it sparays clear

                2 or as i do i use a product called "Spray Away" This is an Aerosol can containing solvents and 1% machine oil this quickly blasts away any paint build up around the nozzle and will clean out the paint cup in seconds, then a final squirt in the cup blow it through and your ready to continue.

                A few tips for you all to save future problems

                (a) dont use old paint it seperates and it will clog up your brush as quick as cyno would.

                (b) make sure your paint is adequately thinned, the consistency of milk is about right! If not use white spirit with enamels or distilled water or alcohol with acrylics (bear in mind though acrylics with some alcohol base will dry very quickly so dont stop spraying untill your finished!

                Comment

                • Guest

                  #23
                  My first attempts at spraying are, to be honest HORENDOUS. Firstly the blooming thing kept stopping and starting. Then it stopped working altogether. I thought it might be the air pressure so i turned it up on the compressor. Started spraying again, but holy cow it came out in a torrent...then stopped again. So after reading your tutorial agian i strained the paint through my girlys old tights and what do ya know? lumpy bloomin paint!!!!! I thought (wrongly) that with it being new paint and clean cups, i would be ok. all through this i kept looking at my paintbrushes....I swear they were laughing at me.

                  Comment

                  • Guest

                    #24
                    my first attempts were not very good, they still arent come to thing of it, i have only done it a few times, my skyline (see gallery) was done with a ts which came out beautifully, but my flakpanza did not come out too well, i dont have pictures of that up yet but i will but them up some time this week!

                    any chance of that video tutorial nigel?

                    Comment

                    • Guest

                      #25
                      It will come soon im gonna do it on the spit

                      Comment

                      • Guest

                        #26
                        great idea!!!

                        Comment

                        • Guest

                          #27
                          Some great advice here, thanks for posting all this! should help me out a fair bit.

                          Whatever happened to the videos? lol

                          Comment

                          • Guest

                            #28
                            Still no sign of those video tutorials?

                            It would be good to watch someone at work who knows what they are doing for some advice, prior to working on a few old models.

                            Comment

                            • Guest

                              #29
                              Some good advice here. Thanks.

                              :smile:

                              Comment

                              • Guest

                                #30
                                Oh wow! I joined your Forum just mimutes ago and have already had nuggets of pur gold - thank you just isn't sufficient!

                                The Gentleman giving an airbrush tutorial has, at a stroke, solved the problems which have left me staring at a brand new

                                compressor etc for 6 odd months unwilling to risk a bash at using it. Not any more!! Thank you so much sir.kind regards 'buggins'

                                Comment

                                Working...